// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_MOJO_SERVICES_DEMUXER_STREAM_PROVIDER_SHIM_H_
#define MEDIA_MOJO_SERVICES_DEMUXER_STREAM_PROVIDER_SHIM_H_

#include <stddef.h>

#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/scoped_vector.h"
#include "base/memory/weak_ptr.h"
#include "media/base/demuxer_stream_provider.h"
#include "media/mojo/services/mojo_demuxer_stream_adapter.h"

namespace media {

// DemuxerStreamProvider shim for mojom::DemuxerStreams.
class DemuxerStreamProviderShim : public DemuxerStreamProvider {
public:
    // Constructs the shim; at least a single audio or video stream must be
    // provided.  |demuxer_ready_cb| will be called once the streams have been
    // initialized.  Calling any method before then is an error.
    DemuxerStreamProviderShim(mojom::DemuxerStreamPtr audio,
        mojom::DemuxerStreamPtr video,
        const base::Closure& demuxer_ready_cb);
    ~DemuxerStreamProviderShim() override;

    // DemuxerStreamProvider interface.
    DemuxerStream* GetStream(DemuxerStream::Type type) override;

private:
    // Called as each mojom::DemuxerStream becomes ready.  Once all streams
    // are ready it will fire the |demuxer_ready_cb_| provided during
    // construction.
    void OnStreamReady();

    // Stored copy the ready callback provided during construction; cleared once
    // all streams are ready.
    base::Closure demuxer_ready_cb_;

    // Scoped container for demuxer stream adapters which interface with the
    // mojo level demuxer streams.  |streams_ready_| tracks how many streams are
    // ready and is used by OnStreamReady() to know when |demuxer_ready_cb_|
    // should be fired.
    ScopedVector<MojoDemuxerStreamAdapter> streams_;
    size_t streams_ready_;

    // WeakPtrFactorys must always be the last member variable.
    base::WeakPtrFactory<DemuxerStreamProviderShim> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(DemuxerStreamProviderShim);
};

} // namespace media

#endif // MEDIA_MOJO_SERVICES_DEMUXER_STREAM_PROVIDER_SHIM_H_
